Attachment system for cables, in particular for wind turbines

ABSTRACT

Attachment system for cables, in particular for wind turbines 
     An attachment system for cables ( 7 ), in particular for wind turbines, having a base body ( 1, 3 ) which can be secured to a support structure and which forms cable bushings ( 5 ) which have an opening for the insertion of cables ( 7 ) and which can be closed by a cover means ( 17 ) by which a retaining force can be applied to the cables ( 7 ), is characterized in that the cable bushings ( 5 ) on the base body ( 1, 3 ) are located in an arrangement which extends at least over part of a ring, with an outside opening and that the cover means ( 17 ) has retaining bodies which can be locked to the base body ( 1, 3 ) for preliminary fixing of the cables ( 7 ) inserted into the cable bushings ( 5 ), and a tightening strap ( 17 ) which encompasses the base body ( 1, 3 ) and which applies a retaining force to the cables ( 7 ) via the retaining bodies.

The invention relates to an attachment system for cables, in particular for wind turbines, having a base body which can be secured to a support structure and which forms cable bushings which have an opening for the insertion of cables and which can be closed by a cover means by which a retaining force can be applied to the cables.

In order to deliver the energy produced in wind turbines and for other operating purposes, such as control, monitoring, and the like, cables which lead through the tower into the nacelle can be reliably secured to the corresponding support structures, especially the tower segments. Usually, attachments with clamp-like base bodies are used for this purpose, in which the cables which have been inserted into them can be secured. These attachment systems in which a corresponding number of screwing processes must be carried out require high mounting effort. This applies especially to the attachment of cables which are routed from below through the tower to the nacelle and which are to be connected to the generator unit. In conventional wind turbines, this generator unit together with the nacelle can execute up to three revolutions before the nacelle is set back. So that the cables can also execute the motion, they are routed over a cable loop hanging into the tower. So that the cables do not chafe one another during rotary motion, the cables must be kept at a distance from each other. For this purpose, the cables are conventionally held by way of a round support structure, for example, in the form of a pipe section around which the cables are distributed and attached thereto with simple clamps. This type of installation which takes place at a considerable height is very complex.

In this respect, the object of the invention is to make available an attachment system which is especially suited to the application under consideration.

According to the invention, this object is achieved by an attachment system having the features of claim 1 in its entirety.

Accordingly, one important particular of the invention consists in that to form a cable loop which hangs from the nacelle into the tower, the cable bushings on the base body are located in an arrangement which extends over at least one part of a ring, with an opening situated on the outside. In that, according to the invention, there are moreover retaining bodies as a component of the cover means which can be locked to the base body for preliminary fixing of the cables inserted into the cable bushings, the cables can be easily inserted in succession into the cable bushings since they are protected against falling out. Since the cover means furthermore has a tightening strap which applies the retaining force to the cables via the retaining bodies, only a single screw connection process for tensioning the tightening strap is necessary to secure all the cables held in the ring arrangement.

As one preferred embodiment, the base body can have the shape of a circular ring body with an inner ring which can be attached to a preferably round support part and an outer ring which surrounds the inner ring at a distance and which forms the cable bushings. The cables fixed thereto thus form a cable ring with a corresponding radial distance to the support part so that a cable group of relatively large diameter with a correspondingly large number of individual cables can be formed.

For attachment of the base body to a flat support structure, the arrangement can be advantageously made such that the base body has a ring part which forms the cable bushings and which extends over part of a circular line, and whose ends are connected by a crosspiece which is integral with it in the form of a straight beam which is connected to the support part in the form of a bracket whose ends project over the respective end of the beam, and that the ends of the tightening strap are anchored to the projecting ends.

While the ring body or the ring part preferably form a full circle or a partial circle, it goes without saying that a non-round, for example, polygonal, ring shape is possible.

In especially advantageous exemplary embodiments, the base body can have cable bushings in the form of tub-like trough-shaped bodies which are connected to one another by wall parts extending in the peripheral direction. In such a configuration, the arrangement must be such that the retaining bodies have a clamping part which projects into the opening of the trough-shaped bodies in the operating position and which forms a contact surface which applies the retaining force to the respective cables.

The arrangement can be especially advantageously made such that the cover surface of the retaining bodies opposite the contact surface as the bearing surface of the tightening strap has an arch which is matched to the peripheral circular line of the outer ring. The cover surface of the retaining bodies which is shaped in this way forms not only protection against the tightening strap, but also forms a part of an imaginary peripheral cylindrical surface of the outer ring for optimum flat contact of the tightening strap.

With respect to the configuration of the outer ring, the arrangement can be advantageously made such that the outer ring between the trough-shaped bodies has two wall parts, each of which delimits the axial outer sides of the outer ring and in which on both sides of the trough-shaped bodies there are recesses which are radially open to the outside and in which catches are made so that the retaining bodies can be protected against motion directed radially to the outside with catch projections which are provided on the parts of the retaining bodies overlapping the trough-shaped bodies. Advantageously, in this exemplary embodiment, the wall parts on both sides of the contact surface which is located on the cover surface of the retaining bodies can form guide surfaces for lateral guidance of the tightening strap.

In other advantageous exemplary embodiments, the arrangement can also be such that the trough-shaped bodies on their outer sides which can be overlapped by parts of the retaining bodies have projections which are made such that the retaining bodies with the catch projections located thereon can be secured against motion directed radially to the outside.

In such exemplary embodiments, the cover surface of the retaining parts can have radially protruding guide projections which form guide surfaces for lateral guidance of the tightening strap.

The retaining bodies can be made as one-piece injection moldings, but can alternatively be formed from two identically made parts which can be connected to one another, of which each part has protruding guide projections as guide surfaces for each side of the tightening.

The invention is detailed below using exemplary embodiments shown in the drawings.

FIG. 1 shows a perspective oblique view of one exemplary embodiment of the attachment system according to the invention, the attachment of only three cables being indicated by way of example;

FIG. 2 shows an enlarged extract of only one peripheral segment from FIG. 2;

FIG. 3 shows a representation similar to FIG. 2, a second exemplary embodiment of the invention being shown;

FIG. 4 shows an enlarged perspective oblique view of only one retaining body as a component of the first exemplary embodiment;

FIG. 5 shows a perspective oblique view of a retaining body for the second exemplary embodiment;

FIG. 6 shows a perspective oblique view which shows the retaining body from FIG. 5 in the exploded state;

FIGS. 7 and 8 show a side view and a perspective oblique view of a third exemplary embodiment; and

FIG. 9 shows an enlarged, opened, perspective oblique view of a retaining body for the third exemplary embodiment.

In FIG. 1, which shows a first exemplary embodiment of the invention in its entirety, there is a base body in the form of a circular ring body with an inner ring 1 and an outer ring 3. Distributed around the entire periphery of the outer ring 3, there is a series of cable bushings 5 which are not all numbered in FIG. 1. In FIG. 1, for example, cables 7 are inserted into only three of the cable bushings 5.

The other cable bushings 5 are shown without the cables inserted, for the sake of clarity of the drawings. The inner ring 1 and outer ring 3 are kept at a distance from one another by way of radially running braces 9 (only some of which are numbered in FIG. 1). The attachment star formed from the inner ring 1 and outer ring 3 is made as a one-piece injection molding. Details of the configuration of the cable bushings 5 and of the cover means which interact with the cable bushings 5 on their opening are shown in FIGS. 2 and 4.

As FIG. 2 shows, the cable bushings 5 are formed by trough-shaped bodies 11 (not all numbered in FIG. 1) in the form of troughs which are radially open to the outside and which are connected to one another by wall parts 13 which form the axially outside boundary of the outer ring 3. The cover means for the cable bushings 5 consists of one retaining body 15 for each cable bushing 5 and a tightening strap 17 which is provided for all cable bushings 5, which extends over the entire outer periphery of the outer ring 3 and, as is conventional for tightening straps, can be tightened by a tensioning means 19 which can be actuated by means of a clamping screw. FIG. 4 separately shows one of the retaining bodies 15 for the first exemplary embodiment in the form of a one-piece injection molding with a central clamping part 21 which, when the retaining body 15 has been moved into the operating position for preliminary fixing of the cable 7 which has been inserted into the pertinent cable bushing 5, engages the pertinent cable bushing 5 with one contact surface 23 and adjoins the pertinent cable 7. The top of the retaining bodies 15 which is opposite the contact surface 23 forms an arched cover surface 25 for contact with the tightening strap 17, the arch being matched to the peripheral round shape of the outer ring 3. Laterally from the clamping part 21, there are fixing parts 27 which are angled relative to the cover surface 25 and on whose free ends catch projections 29 facing one another are formed. In the wall parts 13 which run between the trough-shaped bodies 11 on both sides of the trough-shaped bodies 11, there are recesses 31 which are open radially to the outside and which, when the retaining bodies 15 are attached, their fixing parts 27 engage. In the recesses 31, there are catches 33 to which the catch projections 29 of the retaining bodies 15 can be locked such that motion, which is directed radially to the outside, is possible as a tensioning motion for transfer of the retaining force from the contact surface 23 to the pertinent cable 7; however, the retaining bodies are protected against falling out of the cable bushings 5 before the tightening strap 17 is applied and the pertinent cables 7 are therefore fixed beforehand. As the lateral guide for the tightening strap 17, the wall parts 13 which run between the trough-shaped bodies 11 on the inside form guide surfaces 35 for lateral guidance of the tightening strap 17.

The second exemplary embodiment shown in FIGS. 3, 5, and 6 differs from the first exemplary embodiment in that the connection between the trough-shaped bodies 11 is formed, not by lateral, axially outside wall parts 13, but by centrally positioned wall parts 41 which end at a radial distance from the opening of the trough-shaped bodies 11, so that the outer sides 43 on the opening edge of the trough-shaped bodies 11 are exposed. As FIG. 3 clearly shows, on these outer sides 43 are the catches 33 for locking to the retaining bodies 15. In this exemplary embodiment, the retaining bodies 15, whose shape is detailed in FIGS. 5 and 6, with their fixing parts 27 above the edge of the wall parts 41 overlap the outer sides 43 of the trough-shaped bodies 11 for locking engagement of the catch projections 29 with the catches 33. As FIGS. 5 and 6 show, the retaining body 15 in this example is made in two parts from identical parts which can be locked to one another by means of catch strips 45.

In the absence of the axially outer wall parts 13 which form the guide of the tightening strap 17 in the first exemplary embodiment, on the cover surface 25 of the retaining bodies 15, shown separately in FIGS. 5 and 6, there are radially protruding guide projections 47 for forming the lateral guide surfaces 35 for the tightening strap 17.

In order to prevent kinking of the tightening strap 17 between the succeeding trough-shaped bodies 11, there are bearing pieces 49 on the upper edge of the wall parts 41 in the gap regions between succeeding trough-shaped bodies 11.

The other exemplary embodiment shown in FIGS. 7 to 9 is especially well suited for attachment to a flat support structure. Instead of the base body 1 shown above, which forms a complete, closed, circular ring, in this exemplary embodiment there is a base body in the form of a ring part 51 which extends over only part of a circular line. The ends of the ring part 51 are connected by way of a crosspiece which is integral with the ring part 51 in the form of a straight beam 53 which in turn is screwed to a bracket 55 which, in the form of a flat steel strip, adjoins the underside of the beam 53 over the entire surface, the ends 57 and 59 of the bracket 55 extending beyond the ends of the ring part 51 and on their respective end segments having an offset 61 for support and attachment to a support structure. In proximity to the offsets 71, in the bracket 55 there are longitudinal slots 65 which are used as anchor points for the tensioning means 19 for the tightening strap 17 which is guided over the retaining parts 15 as in the aforementioned exemplary embodiments.

Another difference compared to the above-described exemplary embodiments is that the clamping parts 21 of the retaining bodies 15 intended for clamping of the cables 7 are not located rigidly on the retaining bodies, but that the clamping parts 21 are movably guided in a spring housing 71 and are pretensioned by a spring assembly of several compression springs 63 in the direction to the cable 7 which is to be clamped. As FIG. 9 shows, the clamping part 21 has the shape of a rectangular plate, from whose corner regions guide strips 65 extend into the spring housing 71 and are movably guided therein in guideways 67. To limit the spring path and to prevent emergence of the clamping part 21 which is loaded by the spring assembly from the spring housing 71, there are stop projections 73 and 75 on the guide 67 of the housing and the guide strips 65 of the clamping part 21. As in the above-described exemplary embodiments, the retaining bodies 15 can be secured on the ring part 51 which forms the base body for preliminary fixing of the retaining bodies 15. For this purpose, on the corner regions of the spring housing 71, there are locking strips 77 which correspond to the fixing parts 27 of the above-described examples and form catch projection 79 which correspond to the catch projections 29 of the above-described examples. 

1. An attachment system for cables (7), in particular for wind turbines, having a base body (1, 3, 51) which can be secured to a support structure (55) and which forms cable bushings (5) which have an opening for the insertion of cables (7) and which can be closed by a cover means (15, 17) by which a retaining force can be applied to the cables (7), characterized in that the cable bushings (5) on the base body (1, 3) are located in an arrangement which extends over at least part of a ring, with an outside opening and that the cover means (15, 17) has retaining bodies (15) which can be locked to the base body (1, 3) for preliminary fixing of the cables (7) inserted into the cable bushings (5), and a tightening strap (17) which encompasses the base body (1, 3) and which applies the retaining force to the cables (7) via the retaining bodies (15).
 2. The attachment system according to claim 1, characterized in that the base body (1, 3) has the shape of a circular ring body with an inner ring (1) which can be attached to a preferably round support part and an outer ring (3) which surrounds the inner ring at a distance and which forms the cable bushings (5).
 3. The attachment system according to claim 1, characterized in that the base body has a ring part (51) which forms the cable bushings (5) and which extends over part of a circular line, and whose ends are connected by a crosspiece which is integral with it in the form of a straight beam (53) which is connected to the support part in the form of a bracket (55) whose ends (57, 59) project over the respective end of the beam (53), and that the ends of the tightening strap (17) are anchored to the projecting ends (57, 59).
 4. The attachment system according to claim 1, characterized in that the base body (1, 3, 51) has cable bushings (5) in the form of tub-like trough-shaped bodies (11) which are connected to one another by the wall parts (13, 41) which extend in the peripheral direction.
 5. The attachment system according to claim 1, characterized in that the retaining bodies (15) have a clamping part (21) which projects into the opening of the trough-shaped bodies (11) in the operating position and which forms a contact surface (23) which applies the retaining force to the respective cables (7).
 6. The attachment system according to claim 1, characterized in that the cover surface (25) of the retaining bodies (15) which is opposite the contact surface (23) as the bearing surface of the tightening strap (17) has an arch which is matched to the peripheral circular line of the outer ring (3).
 7. The attachment system according to claim 1, characterized in that the outer ring (3) between the trough-shaped bodies (11) has two wall parts (13), each of which delimits the axial outer sides of the outer ring (3) and in which on both sides of the trough-shaped bodies (11) there are recesses (31) which are radially open to the outside and in which catches (33) are made such that the retaining bodies (15) can be protected against motion directed radially to the outside with catch projections (29) which are provided on the parts (27) of the retaining bodies (15) which overlap the trough-shaped bodies (11).
 8. The attachment system according to claim 1, characterized in that the wall parts (13) on both sides of the contact surface which is located on the cover surface (25) of the retaining bodies (15) form guide surfaces (35) for lateral guidance of the tightening strap (17) on the inside.
 9. The attachment system according to claim 1, characterized in that the trough-shaped bodies (11) on their outer sides (43) which can be overlapped by parts (27) of the retaining bodies (15) have catches (33) which are made such that the retaining bodies (15) with the catch projections (29) located thereon can be protected against motion directed radially to the outside.
 10. The attachment system according to claim 1, characterized in that the cover surface (25) of the retaining bodies (15) has radially protruding guide projections (47) which form guide surfaces (35) for lateral guidance of the tightening strap (17).
 11. The attachment system according to claim 1, characterized in that the retaining bodies (15) are formed from two identically made parts which can be connected to one another, of which each part has protruding guide projections (47) with guide surfaces (35) for each side of the tightening strap (17).
 12. The attachment system according to claim 1, characterized in that the retaining bodies (15) have a spring housing (71) in which the clamping part (21) which forms the contact surface (23) is movably guided and is pretensioned by a spring arrangement (63) in the direction to the cables (7) which are to be clamped. 